Steam-boiler furnace



(No Model.)

J. M. EVANS.

- STEAM BOILER FURNACE. No. 425,309. Patented Apr. 8, 1890.

UNITED STATES PATENT OFFICE.

AMES M. EVANS, OF SPRING VALLEY, NEIV YORK.

STEAM-BOILER FURNACE.

SPECIFICATION forming part Of Letters Patent N0. 425,309, dated April 8, 1890'.

Application filed May 31, 1889. Serial No. 312,712. (No model.)

To all whom it nmy concern:

Be it known that I, JAMES M. EVANS, of Spring Valley, in the county of Rockland and State of New York, have invented a new and useful Improvement in Steam Boiler Furnaces; and I do hereby declare that the following is a full, clear, and exact description of the same.

It is the object of my invention to provide for the perfect combustion of the vapors and gases arising from the bed of coals on the grates of furnaces, and particularly the furnaces used under steam-boilers. It is well known that perfectcombustion is secured by supplying oxygei'i at proper points and in sufficient quantities, and many devices have been devised with this end in view.

In carrying out my invention I aim to supply the oxygen sufficient for perfect combustion directly to the gases being thrown off by a bed of coals, and to heat the air thus supplied, so that it will be of such temperature as to assist combustion instead of retarding it. I use a cylinder or any other suitably-shaped receptacle adapted to the furnace here used, arranged above the grate a suitable distance, with a perforated bottom and a connection to an air-supply for furnishing the necessary oxygen above the surface of the coal upon the grate of the retort or cylinder.

In the accompanyingdrawings, Figure 1 represents a sectional view of an ordinary steamboiler furnace with my improved apparatus in place. Fig. 2 is a detail view of the cylinder, and Fig. 3 is a face view of the furnace, front.

I have shown my invention in connection with an ordinary steam-boiler furnace, and it is adapted for connection. without material change in the boiler or furnace. Between the boiler and grate I interpose the cylinder A, which has its hearings in the end walls of the furnace or fastened to the walls on either or both sides of the furnace. It is provided with a sliding grate, as at c, and the lower part is perforated, as at c, the perforated part being directly above the grate, so as to be in proximity to the bed of coals thereon. The end of the cylinder passes through the front furnace wall, and is provided with a door cl, hinged on one side.

In practice, when the fire in the furnacehas been startedand a light bed of coals on the grate has reached a state of incandescence and the retort has been sufficiently heated, I open the doorof the cylinder or retort and charge it with a sufficient quantity of coal equal to about half its capacity, and then close the door and open a valve or gate of the airpipe g, which is connected with a suitable blower, so as to produce an artificial draft, thus forcing the air through the coal in the cylinder and mingling it with the gases that are now being thrown off from the coal in the cylinder or retort, and both air and gases will be heated sufficiently to ignite as they are forced out of the cylinder and thus come in contact with the incandescent coals of the grate. The perforations c are so situated as to be below the upper level of the coals in the cylinder, and by reason of this the air from the pipe g passes directly down through the entire bed of coals, and is thus caused to completely commingle with the gases thrown oif by said coals, and, further than this, the commingled air and gas in the cylinder pass out in a downward direction, and thus meet the gases on the main coal bed, insuring complete commin glin g and avoiding direct contact with the boiler and cooling the same, as would be the case were the draft of fresh air and gas directed horizontally from the cylinder. During this time I leave the ash-pit doors open, so as to have a natural draft up through the bed of coals on the grate. As soon as the coals in the cylinderhave given oi the greater part of their gases or have become coked I slide the grate in the bottom of the cylinder and empty the contents onto the grate or furnace. Then the grate in the cylinder is returned and the process repeated.

I do not limit myself to a stationary retort, as I may use a revolving cylinder and simply provide it with a hinged cover, which will open when the cylinder is revolved and the coke is dropped out. It will be noticed that the cylinder is located between the two furnaces, and thus acts in connection with each.

I claim as my invention 1. In combination with the furnace, the heating chamber to receive coals for the production of gases, an air-supply communicating ICO with the chamber at a point above the bed of coals therein, said chamber having communication with the furnace through its bottom beneath the bed of coals, whereby the hot air and'gases pass down through the bed of coals and intothe furnace, and a movable grate in said receptacle to permit the discharge of the coked coal of the cylinder onto the main body of coal, substantially as described.

2. In combination with the furnace, the heating-chamber to receive coals for the production of gases, an air-supply communicating with the chamber at a point above the bed of coals therein, said chamber having communication with the furnace through its bottom beneath the bed of coals, whereby the hot air and gases pass down through the bed of coals and into the furnace, substantially as described.

3. In combination, the boiler-furnace, the cylinder A to receive the bed of coals, the said cylinder having perforations inits bottom below the bed of coals, a pipe G, having a valve; and a blower for forcing the air down through the bed of coals, substantially as described. i

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JAMES M. EVANS. v

WVitnesses:

WV. PARKER SMITH, THEODORE B. Bonn. 

